While many industries have shifted towards efficient, on-demand, one-off processes, the textile industry has remained relatively inert. Keeping textile manufacturing on the outskirts of the mass-customization revolution are two barriers—first, the programs used for designing textiles require significant amounts of training, and second, the actual manufacture of the textile is constrained by fixed costs that require the spreading of a design over as many yards as possible, as well as issues of flexibility, making small orders prohibitive from a price stand point. Perhaps the reason why these barriers both remain unfixed is because to remedy one while not fixing the other means either having the ability for mass and costless design of textiles without the manufacturing process to support the effort, or having a manufacturing process ready for on-demand, one-off orders without the design simplicity for orders to actually be submitted. This invention attempts to tackle both issues in order to create an efficient, cost-effective, on-demand, very short-run textile manufacturing process.
A textile has a plurality of warp yarns crossing a plurality of weft yarns, which may be indistinguishable in final fabric form as the intertwining of sheets of thousands of parallel yarns. However, the warp and the weft actually arrive at their crossing point in very different ways. The warp uses a plurality of yarn packages to create its parallel web of yarns, while the weft is merely the repeated insertion of short sections of yarn from a single yarn package. Yarn packages can also be referred to as yarn bobbins, inventoried yarn, or spools of yarn.
Once the warp yarns are introduced to a weaving machine, lifting them for desired weaves and inserting the weft are automatic processes. The only labor needed at the point of weaving is for tying warp yarns when, every once in a while, they happen to break during weaving. The weaving process typically proceeds as follows. First, an inventory of yarn is procured. Those yarns are then collected via a warping method, and that collection is then tied into a weaving machine. In order to properly prepare the warp yarns for the weaving machine, they must be formed into a web of parallel yarns. To do so, yarn packages are placed on creels (racks that hold the yarn packages), properly tensioned, and dragged onto a warp beam. Yarn from these yarn packages is subsequently spun to form sheets of parallel yarns of proper number and length. Each of these methods, however, presents discontinuities in the process of turning yarn into fabric and usually requires many hours of labor.
There are different ways of manipulating yarns into a warp, and each is essentially a trade-off between the amount of time spent placing packages and the amount of time spent rotating a warp beam. We can see the inverse relationship of those costs in three methods—direct beaming (FIG. 2), sectional warping (FIG. 3) and sample warping. In direct beaming, each warp yarn corresponds with a yarn package and the entire width of the warp is accounted for by the creeling of thousands of yarn packages. Therefore, much time is spent placing yarn packages and less time is spent rotating the warp onto the beam. Sectional warping substitutes creeling time for beaming time—fewer yarn packages are placed on the creel (around 80-800), but many sections must be rotated on the warp beam for a textile of equal width. Sample warping is a further extension of this idea. Even fewer yarn packages are placed on the creel (between 1 and 24), but much time is spent rotating the yarn around a drum to build up a warp of equal width. All the aforementioned methods require various degrees of labor, and also present a bottleneck in the process of turning yarn into a warp for weaving.
To enable a more continuous process, the idea of creating a warp beam must be disposed of. In order to go straight from yarn packages to weaving machine, one might employ a method called direct weaving (FIG. 1) or creel weaving, though it has its own limitations. It is the most continuous process as a creel of yarn can go directly into the weaving machine, but it requires much time spent placing yarn packages onto the creel. Furthermore, as the number of yarns in the warp increase, the creel must become physically larger, and the differential in distance between the yarn packages at the front and back of the creel causes a problem. The greater the distance the yarn takes on its path to the weaving machine, the more length of yarn dangling, the greater the weight on the passing yarn, and the greater the tension at the point of weaving. The tension differential between the yarns in the warp causes major problems in weaving, from unsellable, slack or puckering fabric, to broken threads that can slow down or prevent weaving entirely.
It should be clear that the two problems that hold manufacturing efficiency hostage are the heavy labor involvement of setting up a warp, and the discontinuities in the process. Various attempts have been made to deal with these issues. One such model attempts to spread the large set-up costs of warp creation over a few connected, smaller warps by joining yarn lengths to each other, the joints of which mark a transformation from one warp order to the next. This model does nothing to address the discontinuities in creating warp beams and the heavy costs of creeling, and rather uses the idea of batching orders for each order to cost less.
Other frameworks attempt to address the costs of creeling yarn packages, and they can be seen as a relatively direct automation of what laborers would normally do, an approximation of human movements done by a machine. One such attempt simply automates the process of yarn package placement. Instead of a laborer picking up a yarn package, placing it on the creel and tying it to the previous, emptying package, a robot does it. This method requires little labor and maintains a continuity in the warp, but has two downsides: traditional yarn packages cannot support the creel weaving of thousands of yarns because of the tension issues that arise as a result of their size, and having to move to every spot in a creel to place a new package means greater distances must be covered, which makes the process too time-intensive for short-run production. An evolution of this idea is machinery that moves a smaller amount of yarn to each creel spot instead of an entire yarn package. This allows the creel to be small enough for direct weaving to be possible. However, since the yarn loader moves from creel spot to creel spot, there is an immediate and practical limitation on both the speed at which that refilling can take place, as well as the number of yarns that can be accessed for the refilling. The first problem is the result of the distance the loader must travel and its ability to refill a creel fast enough to keep up with a weaving machine that is processing short runs. The second issue is one related to moving a plurality of yarns around a space. As the supply yarns get pulled from one creel spot to the next, the distance between their point of tension and the point at which they're held will invariably change. This will mean that at any point, many of the yarns will have slackness, which will cause major entanglements. It might be suggested that flexible tubes could keep yarns contained to their own spaces and from tangling, but this causes its own tension problems by adding infinite and unpredictable points of contact to the yarn. This functional limitation means the number of accessible yarns must be held to a minimum. A suboptimal weaving system is therefore created, for both inter-warp and intra-warp reasons.
From intra-warp considerations, a reduced availability of inventoried yarns translates into a reduction in the diversity of yarns possible in a section, which limits the extent of the patterning that can be utilized in that section. For example, if a customer wants 40 different colors within the first 100 yarns of the warp, and the inventoried yarns for that section only number into the 20's, then either the customer has to alter the order or a significant amount of operator intervention would be required to change out the yarn packages mid-process. Secondly, depending on how one warp looks compared to the one that follows it (inter-warp), it may be that there are few continuations in color from one order to the next, in which case a laborer would have to take a lot of time replacing the inventoried yarn for the next order. Therefore, a lack of yarn options actually corresponds to an increase of labor to satisfy a diversity of orders, which eliminates the primary advantage of short-run manufacturing.